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Web Security for Network and System Administrators4 Basic Security Concepts Physical security – protect people, equipment, and facilities Privacy – critical data is not released to the wrong people Marketplace perception – the way the company is perceived by customers, partners, and competitors

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Web Security for Network and System Administrators5 Assessing Risk Check existing security policies and processes Analyze, prioritize, and categorize resources by determining: total cost of ownership, internal value, and external value. –TCO refers to the total monetary and labor costs calculated over a specific time period –Internal value refers to the monetary assessment of the importance of a particular asset to the internal working of a company –External value refers to the money or another commodity that the asset brings to the company from external sources

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Web Security for Network and System Administrators6 Assessing Risk Consider business concerns through the annualized loss expectancy (ALE = SLE * ARO) –Single loss expectancy (SLE) is equal to the assets value times the exposure factor (EF) Asset value = TCO + internal value + external value EF is the percentage of asset loss that is expected from a particular threat –Annualized rate of occurrence (ARO) is the estimated frequency with which a particular threat may occur each year

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Web Security for Network and System Administrators7 Assessing Risk Evaluate existing security controls to determine what controls are deployed and effective Leverage existing management and control architecture to build a persuasive business case for, or against, implementing new security controls

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Web Security for Network and System Administrators8 Building a Security Policy A security policy has the following three important benefits: –Communicates a common vision for security throughout a company –Represents a single easy-to-use source of security requirements –Exists as a flexible document that should be updated at least annually to address new security threats

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Web Security for Network and System Administrators9 Building a Security Policy An organizations security policy should cover the following: Foreword: Purpose, scope, responsibilities, and penalties for noncompliance Physical security: Controls to protect the people, equipment, facilities, and computer assets User ID and rights management: Only authorized individuals have access to the necessary systems and network devices

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Web Security for Network and System Administrators10 Building a Security Policy An organizations security policy should cover the following: Network security: Protect the network devices and data in transit System security: Necessary defenses to protect computer systems from compromise Testing: Authorized security tools and testing Auditing: Procedures to periodically check security compliance

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Web Security for Network and System Administrators11 Building a Security Policy Foreword Purpose: Why is this policy being established? Scope: What people, systems, software, information, and facilities are covered? Responsibilities: Who is responsible for the various computing roles in a company? Compliance: What are the penalties for noncompliance? Which organization is responsible for auditing compliance?

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Web Security for Network and System Administrators14 Building a Security Policy Network Security Specific timeframes for changing passwords on the network devices Use of secure network protocols Firewalls at specific chokepoints in a network architecture Use of authentication servers to access network devices

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Web Security for Network and System Administrators15 Building a Security Policy System Security The systems section is used to outline the specific settings required to secure a particular operating system or application –For example, for Windows NT 4.0, it may be a requirement that every logical drive be installed with NTFS –For a particular UNIX flavor, shadow password files may be required to hide user IDs and passwords from general users

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Web Security for Network and System Administrators16 Building a Security Policy Testing and Auditing Specify requirements for vulnerability scanners, compliance checking tools, and other security tools run within the environment Require auditing logs on specific devices, periodic self-audits performed by the system administrators, and the use of security compliance checking tools Specify corporate auditing requirements, frequencies, and organizations

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Web Security for Network and System Administrators19 Summary The CIA triad categorizes aspects of information that must be protected from attacks: confidentiality, integrity, and availability. The PPP triad depicts security, privacy, and marketplace perception as three additional abstract concepts that should drive security efforts.

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Web Security for Network and System Administrators20 Summary The first step in creating an effective security policy is to perform a risk assessment within the environment. A risk assessment consists of five steps: –Check for existing security policies and processes –Analyze, prioritize, and categorize resources –Consider business concerns –Evaluate existing security controls –Leverage existing management and control architecture To estimate potential financial loss from security threats, the following formula works well by accounting for the most important cost factors associated with security: ALE = SLE * ARO. A security policy has three major benefits. It: –Communicates a common vision for security throughout a company –Represents a single easy-to-use source of security requirements –Exists as a flexible document that should be updated at least annually to address new security threats

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Web Security for Network and System Administrators21 Summary An effective security policy includes security requirements in the following areas: –Physical security –User ID and rights management –Systems –Network –Security tools –Auditing There are a number of security-related certifications to help security professionals quantify their knowledge on a resume. Every security professional must stay current about the latest threats through Web resources, mailing lists, and printed materials.